LOCOMOTOR ATAXIA.
Synonyms.—Posterior spinal sclerosis; tales dorsalis.
Definition.—An organic disease of the periphero-central sensory nervous system characterized symptomatically by inco ordination, sensory and trophie disturb ances; affections of special nerves, the optic and ocular particularly; and in volvement of the sphincters.
Varieties. — In its classical form the symptom-complex in posterior spinal sclerosis is exceedingly constant. There are variations in the clinico-pathological picture, however, which justify a clas sification into at least three types: the common, or typical; the anomalous, or atypical; and the complicated. In typical cases the symptoms point to a primary disease of the sensory neurons of cer tain areas of the lower dorsal and lum bar cord (common type). Occasionally, though rarely, the primary invasion is of the upper or cervical cord (cervical or superior tabes), and in still others the initial symptom may be an optic atrophy (amaurotic tabes, initial optic-atrophy type). The predominance and persist ence of pain in certain cases has served as the basis for a so-called neuralgic type (tabes dolorosa, Rcmak), while the early development of general or pseudopara plegic muscular weakness, which becomes rapidly prominent, affords a basis for the recognition of the so-called paralytic type. True motor paralysis is not an essential part of tabes, however, except as a late secondary phenomenon. Occur ring early, it indicates the existence of a complication. Erratic extensions of the disease into other areas of the cord give rise to anomalous symptoms, which are considered elsewhere under the head of COMPLICATIONS. The terms acute, se vere, and mild appear in the literature of the subject, but are unimportant in significance.
Symptoms, — The symptomatic study of tabes dorsalis may be divided into at least two stages: the incipient, or pre ataxic, and the ataxic. The line of de markation is so indistinct and ill defined clinically, however, as scarcely to justify separate consideration, and I shall there fore describe the clinical history as a whole, reserving for a separate analysis of individual symptoms the question of the relation of such symptoms to these two stages.
The disease, as ordinarily observed, begins very insidiously, and its early progress is usually slow. The first sub jective evidence realized by the patient may be a sensation of numbness or other parmsthesioe (tingling, burning, "pins and needles," etc.) occurring in the ex tremities, or, more frequently, attacks, occurring paroxysmally and without warning, of sharp stabbing pains, usu ally in the legs, but without constancy as regards distribution. Slight diminu tion or, rarely, sudden increase in sexual desire or power may be noted about the same time.
Four hundred cases of tabes collected from the private practice of Erb. One hundred of these cases were still in the initial stages. As a primary symptom lancinating pains are most frequently mentioned,-200 times in the legs, 5 times in the back, and once in the arms. Tabes begins, in the majority of instances (67 per cent.), with lancinating pains; nevertheless, these are often not present alone as a first symptom, but are accom panied by one or several others. On the other hand, these lancinating pains may exist for a number of years without the disease manifesting itself in any other way. The frequency of the single symp toms of tabes are given as follows:— Per- centage Failure of patellar reflexes 92.00 Romberg's symptom 88.75 Lancinating pains 88.25 Vesical disturbances 80.50 Ataxia of the legs 74.75 Changes in pupillary reaction 70.25 Parwsthesia of the legs 64.50 1Veakness of the legs and quick fatigue 62.25 Absence of sexual desire 58.25 Changes in size of pupils 48.25 Retarded transmission of pain 36.50 Hyperalgesia of the legs 33.75 Girdle sensation 31.00 Transitory diplopia .26.50 Hypereesthesia of the legs 23.25 Ulnar pareesthesia 16.50 Paralysis of acular muscles 16.00 Atrophy of optic nerve. 6.75 Persistence of pains in the legs 6.00 Crises . 5.25 Arthropathies 1.75 Leimbach (neut. Zeit. f. Nervenh., B. 7, Nos. 5, 6, '95).